Sealed container of surgical ligatures and method of preparing same.



C. T. DAVIS. SEALED CONTAINER 0F SURGICAL LIGATURES AND METHOD OF PREPARING SAME. APPLICATION FILED v5.20. 1915.

' ran s'ra'rns CHARLES T. DAVIS, OF IBROOKLYN, NEW YORK.

SEALED conrhmnn or suncrcnr. rrearunns AND METHOD or PREPARING SAME.

Specification of Letters Patent.

Patented M. ii, rare;

Application filed Ap1i120, 1915. Serial No. 22,643.

This invention relates to surgery, and par- K ticularly to the sterilization, storlng, and

preservation ready for use of surgical ligatures orsutures, suchas employed by surgeons for stitching wounds. and for tying arteries.

While features of the invention may be applicable in' the storing and/preserving of ligatures ofother kinds, by way of illustration, I have described the invention as appliedto ligatures composed of'animal tissue,

' known as catgut. .Such ligatures, of course,

Lone for must be sterilized to prevent any possible infdtion of the wound. The most gen- .erally employed method now in use for sterilizing, storing, and preserving catgut ligatures necessitates the use of two diflerent and one for storing. Under such method, the ligature is first sterilized by immersing in a'heated bathof suitable liquid such as cumol, having a comparatively high boilingpoint. The

surplus cumol is then rinsed off, and the ligatureinclosed'ini a sealed tubecontaining a lighter and more volatile storing liquid such as chloroform or alcohoL- There are many objections to the use of these two lattear-substances, and there is also grave objection to the present method of sterilization because it rende possible, and in fact, likely, the accidental contamination of the ligatures from the necessary handlings 'durl ing the. several steps of manufacture.

Theprincipal object of the present invention is to produce, as an: article of manufacture, asealed tube or container inclosing .a ligature having superior qualities, ,such qualities arising both from the improved process of preparing and sterilizing the ligature, and from the character of the storing liquid employed. To this end, I employ a liquid of such a nature that it will servefor both sterilizing and storing purposes, thus eliminating entirely theuse of two separate liquids, and avoiding any possibility of accidental contamination of the ligaturesbecause permitting the entire process of heat sterilization to be conducted after the tubes during or subsequent to the process of sterilization is entirely eliminated, thus rendering positive the assurance of sterility, and coincidentally efiecting a great economy in the amount of time and skilled effort otherwise required when conducting the process of sterilization and the handling of the'ligatures under aseptic conditions and amid sterile environments, as is necessary when employing the method heretofore in vogue, (z'. c., the sterilization of the ligatures before the sealing of the tubes and the'subsequent filling of the tubes with their content of ste'rile storing fluid y A further specific object of the invention isto provide an improved method of sterilization, whereby the heated storing fluid is forced into the pores and intersticesv of the .ligature under pressure, thereby. sterilizing vthe ligaturelnot only on the surface, but

also throughout the body. thereof.

Further objects of the invention will appear morefully hereinafter.

The invention consists 1n those features -;and combinations. of features described in' detail hereinafter, all, of which contribute. to producean eflicient tubeor container of ligaturs.

AS out my invention, reference is-had to the accompanying drawings, in which,

.ljigure lis a sidelevation-of a tube em; bodying my invention; and, Fig? 2 is a'view similar to Fig. 1, but illustrating the process of sterilizing'the ligature within the tube- Before-proceeding to a detailed description of my invention, consideration should be 'given to the defects of chloroform and alcohol when used as storing, preserving, or

sterilizing fluids in ligature tubes. Chloro-' form has been found objectionable for these purposes for many reasons, chief among which are the following: FirstGhloroform breaks down underfcomparatively moderate illustrating the methodv of carrying heat into 'chlorin and hydrochloric acid, both of which exert an extremely harmful effect upon the ligatures. Second-Under the influence of sunlight, free chlorin, hydrochloric acid and carbonyl chlorid (phosgene) are liberated, the latter product in particular being extremely objectionable. Third. The disagreeably irritating and harmful effect of chloroform upon the tissues. Fourth-The inadequately low boiling point of chloroform, which prevents the successful application of the temperature necessary for the sterilization of the tubes after being sealed. Fifth-The susceptibility of chloroform to deterioration from age. Sixth -Chloroform can hold water in solution, which is very harmfuhto the ligatures, particularly to that kind of ligature most widely used, namely, catgut, for as is well known,

.the slightest degree of moisture tends to convert the collogen in the catgut into gelatin, with the result that when the catgut is subjected to thermal sterilization, it becomes brittle, weakened, and twisted.

Alcohol is objectionable for many reasons, chief among which are its low-boiling point, its inefficacy as a solvent of the fatty matter of the ligatures, and for the further reason that, as is well known, alcohol has a strong affinity for water, and hence it is difficult to secure alcohol which is perfectly free from water. As above stated, the presence of even a; minute quantity of water in-the storing liquid tends to convert. the collogen of the. gut into gelatin, with the result that when the gut is subjected to any adequate sterilizing temperature, such as 100 0. (212 Fahrenheit) or over, it becomes brittle, weakened, and twisted.

In order to overcome the difliculties and objections mentioned above, the combination sterilizing and storing liquid employed should possess the following characteristics: 'It must have a boiling point sufficiently high to permit of sterilization of the contents ofthe sealed tube at an adequate temperature,

and at the same time, sufficiently low to admit of rapid evaporation when the ligature is removed from the tube; it-must be absolutely non-irritating to thetissues of the body; it must be entirely stable and not subject to deterioration under the influence of heat, light, or time; moreover, it must be incapable of holding water in solution, and

should-even preferably be water-repellant.

I have discovered that the benzene series of hydrocarbons, and especially the lower methyl-substitution products thereof, answer the above requirements to a remarkable degree. Benzol itself, having the formula C I'I may be employed to advantage, as

well as mono-methyl benzene C H CI-I or any of the three di-methyl benzenes. The mono-methyl product is known as toluol or toluene, and the di-methyl products as ortho-, meta-, and para-Xylol or xylene. Mixtures of any or all of these substances may also be used successfully.

The above compounds, being in the nature of light, volatile oils, will not hold water in solution, and are absolutely stable and inert at ordinary temperatures. Moreover, they are powerful solvents for oils and fats, and are therefore very eflicient in removing the fats and fatty acids occurring in catgut ligaw tures, and which are irritating to the tissues of the body.

In producing a tube of ligatures according to my invention, I prefer to provide a tube 'or container'l, of any suitable substance, such as glass, which will resist the high temperature necessary for sterilizing the contents. The first step necessary is to insert the strand or strands of catgut or other ligature material, suitably wound or coiled, within the tube or container. Next,

the moisture is removed from the ligaturev by any suitable dehydrating process, this 1 being a very necessary step for the reason previously explained. Then I place within tion of the volume of the tube, for reasons which will appear more fully hereinafter. I then slightly heat the tube so as to cause vaporization of the liquid, and then while the upper part of the tube is filled with the vapors of the liquid, I hermetically seal the tube, preferably by fusing and closing its end in a well known manner. By slightly heating the tube and simultaneously sealing it in this way, I insure that a vacuum is created within the tube upon the condensation of the vapors. With the tubes ealedin this way and containing this substance, it is also assured that the interior of the tube will be devoid of water, because the presence of water in the substance is immediately indicated by the substance itself, which, as sug gested above, will notmix with water.

After the tube or container. has been sealed as suggested, I therf effect the sterilization by heating it to a sufficiently high'temperature to sterilize the contents- The substance toluol boils at about 111 centigrade; the product'benzol, the base or nucleus of the benzene or aromatic series of hydrocarbons, boils at about 80 0.; while the di-methyl ben'zenes, ortho-Xylene, meta-Xylene, and para-Xylene, boil at from about 137 to 143 C. The substances named, and various mixtures thereof in different proportions, all have a boiling point between 80 C. and 143 0., and these temperatures mark "substantially the practical limits within which the invention can be successfully carried out,

although 1n some cases, a product having a boiling point even below 80 C. may be employed. Furthermore, these substances have The temperature employed for steriliza-.

tion varies with the nature of the particular liquid used, but is always substantially above the normal boiling point of such liquid, and in no case less than 100 C. For example, in using toluol, which boils at 232 F. (111 C.) a temperature of between 240 and 250 F. would be employed, while with benzol, the temperature would not run so high. In each instance, the temperature is raised to such a point as will produce a pressure within the tube sufficient to force the vapor well into the pores of the ligature, and thoroughly impregnate the same. Care must be exercised, however, that the temperature does not rise too high, as there is danger of bursting the tube by excessive pressure. The pressure is automatically regulated to some extent, perhaps, by reason of the fact that as the pressure rises, it naturally tends to check ebullition and prevent the further giving off of vapor.

By reason of the fact'that I employ a small volume of liquid as suggested,there is a relatively large space in the tube above the surface of the liquid, which will become filled with dense vapors 4 when the proper degreeof heat is applied, and the effect of this is to force the vapors under pressure through the capillary interstices of the-ligature, and in sucha way as to impregnate such interstices or cells of the ligature with the vapors of the substance, thus not only contributm to the most thorough sterilization of the ligature, but at the same time increasing its flexibility,'the latter a most im portant consideration. the tube is. of course, in contact with the ligature, but the ligature preferably extends up to a height in the tube so that a large part of the ligature may be exposed above the level of the liquid, it being understood that the vapor created by boiling the fluid will rise and completely envelop the ligature, thus effecting, with but a very small quantity of liquid, equally as eflicient sterilization as though the llgature were completely submerged." -.'l :his effects a decided economy in the costlgof such tubes or con.- tainers of ligatures, because of the relatively small quantity ofthe fluid employed.

, gives off The liquid within- My invention renders possible the very desirable procedure of sterilizing the exterior of the tubes by boiling in water'along with the surgical instruments preliminary to operating.

What I claim is:'

1. As a new article of manufacture, at hermetically sealed glass container holding a ligature with a highly volatile hydrocarbon liquid within said container having a volume which is a fraction of the volume of said container, the interior of said container being devoid of water, and substantially devoid of air. A

2. As an article of manufacture, at hermetically sealed glass tube containing a ligature, anda liquidhy'drocarbon having a boiling point between 80 and 143 C.

3. As an article of manufacture, a hermetically sealed glass tube containing a ligature and a liquid incapable of mixing with water, such liquid having a boiling point suiiiciently high to admit of the tube being heated to at least 100 C. without generating dangerous pressures within the same.

4:. As an article of manufacture, a hermetically sealed glass tube containing a ligature, and a stable, volatile, preserving and storing liquid, said liquid having a volume which is a small fraction of the volume of the tube, whereby a relatively large space is presented within the tube to hold the vapors of said liquid, when the tube is heated.

5. The method of preserving surgical ligatures which consists in placing the ligature in a container together with a quantity of a stable, inert storing liquid, the volume of the liquid being less than that of the container, heating the container until the liquid vapor in such quantity as to expel the air, and then sealing the container while filled with the vapor, whereby air is substantially excluded. V

6. The method of sterilizing and storing surglcal ligatures which consists in inclos-' 'ing the ligature in a sealed container together with a stable, inert, preserving liquid,

the volume of the liquid being only a small fraction of that of the container, and then heating the container to a point substantially above the boiling point of the inclosed liquid, whereby vapor pressure is generated within the container, and the vapor thus caused to penetrate the pores of the ligature. I

8. The hereifi described method of preserving surgical ligatures and the like'which tially filling such container with a liquid having a boiling point above 80 centigrade and capable ofdissolving fats hermetically sealing the container and then Sub ecting the sealed container and its contents to a suitable sterilizing heat above the boiling point of said liquid.

1b 9. The hereindescribed method of treating surgical ligatures which consists in subjecting them to the action of a hydrocarbonvapor under pressure, and above a temperature of 100 C.

In testimony whereof I have afiixed my signature, in presence of two witnesses.

CHARLES T. DAVIS. Witnesses E. C. PInRsoN; BENJAMIN F. HIRSCHV 

